Field of the Invention
The present disclosure relates to an image forming apparatus and a controlling method, more particularly to an image forming apparatus having a mass storage device as a secondary storage device and a method for controlling the image forming apparatus.
Description of the Related Art
There has been a processing device provided with a mass storage device such as an HDD (Hard Disk Drive), an SSD (Solid State Drive), or the like as a secondary storage device. Such a processing device accesses a primary storage, which is also referred to as a main memory, when it stores and reads data into and from a mass storage device which is a secondary storage device. In other words, the processing device reserves a storing buffer in the main memory when it stores data into the mass storage device, and reserves a reading buffer when it reads data from the mass storage device. Further, there has been a known technique of using a reading buffer of a main memory as a second storing buffer and using a regular storing buffer and the second storing buffer as toggle buffers to increase a storage speed when data is to be stored into a mass storage device.
For example, operations of an image forming apparatus include an operation of performing image forming for printing after completing reading of all pages of a document. The operation described above may be, for example, so-called booklet printing of arranging image data of each page such that a booklet can be obtained when printed objects are stacked and valley-folded in a lengthwise direction, printing of adding images such as page numbers associated with all of pages, or the like. When the image forming apparatus receives other print job before completion of an operation of reading a document, it can perform a printing operation for the print job in parallel with the operation of reading a document of the previous job. However, if the image forming apparatus performs the printing operation for the later print job in parallel with the reading operation for the previous job, the order of job processing becomes different from the order of job receiving. Therefore, the image forming apparatus is configured so as not to start processing of other job until the processing of the previous job is completed even when a next job is received before completion of the reading operation.
In this case, there has been a problem that the image forming apparatus becomes slow in the reading operation for the previous job and also becomes slow in starting of processing for the next job if the reading buffer of the main memory is not used as the second storing buffer in the operation of storing into the mass storage device the image data obtained by reading the previous job, in other words, if the toggle buffer method is not employed.
Therefore, application of the toggle buffer method to the image forming apparatus is considered.
If the image forming apparatus uses the toggle buffer method to execute Scan-To-Box (the operation of storing image data, which is obtained by executing a scanning operation, into the mass storage device), the reading buffer of the main memory is used as the second storing buffer in addition to the storing buffer. Accordingly, the storage speed of storing image data into the mass storage device can be increased.
During the execution of this operation, there is a case where an instruction of operation with reading from the mass storage device, such as Box-To-Print (the operation of reading image data from the memory device and printing the same), is given. In this case, the image forming apparatus already uses the reading buffer of the memory as the second storing buffer through the operation described above. Therefore, the image forming apparatus cannot start the reading operation with use of the reading buffer, such as the BOX-to-PRINT, until the reading buffer is provided, in other words, until the previous storing operation is completed. Therefore, there has been a problem that starting of the next printing is delayed.